<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<script>
		// var iNum = 12;
		// var sTr = 'abc';
		// alert(iNum);
		// alert(sTr);
		var iNum;
		alert(iNum);
	</script>
</head>
<body>
	
</body>
</html>